Code element identification method and apparatus

ABSTRACT

An improved code element identification method and apparatus wherein a code element assembly receives an interrogate signal from a code identifier assembly in an activated position of the code identifier assembly when the code element assembly is positioned in a code identifying proximity with the code identifier assembly, the code element assembly emitting a time oriented encoded responder signal in response to the received interrogate signal. The code identifier assembly receives and decodes the responder signal and generates a code valid signal in response to an identified code encoded in the received responder signal and a foreign code signal in response to an unidentified code encoded in the received responder signal. In one aspect, the present invention also contemplates an improved binary encoder module receiving a clock signal of a predetermined frequency and emitting an output signal encoded with a predetermined code.

United States Patent [191 Freeny, Jr.

[ Aug. 13, 1974 CODE ELEMENT IDENTIFICATION METHOD AND APPARATUS [75] Inventor: Charles C. Freeny, Jr., Fort Worth,

Tex.

[73] Assignee: Information Identification Company,

Inc., Ft. Worth, Tex.

[22] Filed: Oct. 24, 1972 [21] Appl. No.: 300,098

[52] US. Cl 340/149 R [51] Int. Cl. H0451 3/02, 60615 17/00 [58] Field of Search..... 340/149 R, 164 R, 147 MD; 235/61. 12

[56] References Cited UNITED STATES PATENTS 3,544,769 12/1970 Hedin 340/149 R X 3,622,991 11/1971 Lehrer 3,641,498 2/1972 Hedin 340/164 R 3,662,342 5/1972 Hedin et a1. 340/149 R X 3,673,569 6/1972 Hedin et a1. 340/149 R X 3,688,269 8/1972 Miller 340/149 R 3,700,859 10/1972 Laurer et a1. 235/6l.l2 N X 3,702,464 11/1972 CastruccL. 235/6l.l2 N X 3,764,742 10/1973 Abbott et al 340/149 A Primary ExaminerDonald J. Yusko Attorney, Agent, or Firm-Dunlap, Laney, Hessin, Dougherty & Codding 5 7] ABSTRACT An improved code element identification method and apparatus wherein a code element assembly receives an interrogate signal from a code identifier assembly in an activated position of the code identifier assembly when the code element assembly is positioned in a code identifying proximity with the code identifier assembly, the code element assembly emitting a time oriented encoded responder signal in response to the received interrogate signal. The code identifier assembly receives and decodes the responder signal and generates a code valid signal in response to an identified code encoded in the received responder signal and a foreign code signal in response to an unidentified code encoded in the received responder signal. In one aspect, the present invention also contemplates an improved binary encoder module receiving a clock signal of a predetermined frequency and emitting an output signal encoded with a predetermined code.

22 Claims, 7 Drawing Figures CODE ELEMENT IDENTIFICATION METHOD AND APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to improvements in systems for identifying coded elements and, more particularly, but not by way of limitation, to a code element identification method and apparatus wherein the code element emits a time oriented encoded responder signal.

2. Brief Description of the Prior Art In the past, there have been various mechanical and electronic devices constructed in the nature of a key element and key receiving element wherein the-key receiving element received and identified the key element, the key receiving element causing anoutput indication indicating that the received key element was recognized by the key receiving element for unlocking a door or otherwise enabling or disenabling various devices operated in responsie to an indication of an identtified key element. The key elements and key receiving elements constructed in the past have assumed a vari ety of physical constructions and modes of operation ranging generally from the typical mechanical type of key element, having one surface shaped to engage and cooperate with tumblers located in the key receiving element, to keys of a card-like or mechanical-like construction, having a plurality of conducting paths or the like oriented and constructed to cooperate with a portion of the key receiving element to establish a type of code via activating the proper electrical circuits in the key receiving element.

The U.S. Pat. No. 3,633,167, issued to Hedin, disclosed a security system utilizing a key-like element, having a plurality of push-buttons connected to a lock control, the push-buttons activating the lock control to provide access to the secured area when actuated in a predetermined sequence. This particular apparatus was also constructed to generate a signal actuating an alarm when the push-buttons were. actuated in an improper sequence.

The U.S. Pat., No. 3,651,464, issued to Hedin, disclosed an electrical security system utilizing a key-like element and a key receiving element wherein the key element included a plurality of electrical contacts for conveying a binary coded permutation of electrical signals to the key receiving element when the key element was inserted into the key receiving element establishing electrical contact between the key element electrical contacts and conductor paths of the key receiving element. 1n an effort to prevent the deciphering of the key element by an unauthorized person, only some of the key element electrical contacts were connected to a key element control circuitry for conveying the code signal to the keyreceiving element, thereby leaving a number of blank or unused electrical contacts on the key element.

The U.S. Pat., No. 3,544,769, issued to Hedin, disclosed an identification key having coded electrical circuits brought into contact with a computer system for verifying various data relating to a credit card transaction wherein the key element contained a control circuit having a plurality of separate circuit paths arranged to correspond to a predetermined binary code identifying a key. in this system, the key was inserted into a key receptacle in such a manner that the encoded data of the key element was transferred to the recognition networks of the key receiving element. The details of the key-card of this system were disclosed in the U.S. Pat., No. 3,336,635, also issued to Hedin. The U.S. Pat., No. Re.27,0l3, reissued to Hedin, also disclosed a key-actuated electronic security system having a key element and a key receiving element constructed similar to the key receiving elements of the Hedin patents referred to above.

The'U.S. Pat., No. 3,639,906, issued to Tritsch, disclosed a key identification system having a key element insertable into a transmitting apparatus for providing a signal indicative of the code formed in the key element, the signal being received via a code recognition assembly. In this particular apparatus, the key element was formed such that a structural portion thereof engaged a portion of an encoding transmitter and cooperated therewith to cause a signal indicative of the particular code to be transmitted via a transmitter.

The U.S. Pat., No. 3,599,454, issued to Hill, disclosed a mechannical type of key and a key identifier wherein the key included spaded electrical switching elements located thereon to cooperate with a portion of the key identifier assembly for generating a code determined via the on or off position and the sequence of the key element switching devices.

The U.S. Pat., No, 3,668,831, issued to Nicola et a1, disclosed an anti-theft device having a key element containing a plurality of electronic contacts insertable into a lock assembly wherein the electronic contacts of the key element were arranged to provide a code uniquely identifying the particular key element. The electronic contacts of the key element actuated electronic circuitry constructed to identify the code defined via the electronic contacts.

The U.S. Pat., No. 3,628,099, issued to Atkins, disclosed a resistance-responsive control circuit having a discrimination portion and an anti-tampering portion utilized in cooperation with a solenoid-controlled door lock of an automobile. The circuitry was designed such that the door lock of the automobile was actuated via predetermined keying resistances formed on the key element.

The U.S. Pat., No. 3,167,792, issued to Brendemuel, disclosed an electric lock wherein a receptacle included a key way for receiving the key element and a plurality of spaced stationary switch contacts extended into a portion of the key way. The key element included a plurality of switch contacts spaced for engaging the switch contacts of the key receptacle and activating an electronic circuit identifying the key element. The U.S. Pat., No. 2,473,644, issued to Taylor, disclosed an electric locking key device wherein the key element contained a plurality of contact points spaced and positioned thereon to cooperate with contacts located in a key receptacle such that, when the key element was properly positioned in the key operated switch of the key receptacle, the contacts in the key receptacle engaged the contacts of the key element and contacted and activated the key identifying circuit.

The U.S. Pat., No. 3,518,655, issued to Saul, disclosed a security device wherein the key element had a predetermined electrical resistance and the key re ceiving apparatus consisted of an unbalanced bridge connected to an alarm, the insertion of a key element having an incorrect or unidentified electrical resistance The US. Pat., No. 3,355,631, issued to Christiansen, disclosed a removable key-actuated control circuit wherein the key element contained spaced inductance elements cooperating with stagger tuned tank circuits of the key receiving and-identifying assembly, the insertion of a proper key element causing the tank circuits to reasonate at a particular frequency actuating a switching device utilized in cooperation with an electromagnetic locking mechanism.

' Summary of the Invention An object of the invention is to provide an improved code element identification method and apparatus wherein the code element transmits a time oriented responder signal uniquely identifying the code element in a faster, more efficient manner.

Another object of the invention is to provide an improved code element identification method and apparatus having a reduced number of contacts.

One other object of the invention is to provide an improved code element identification method and apparatus wherein the operation of the code generating apparatus of the code element and the code identifier assembly are substantially synchronized in an automatic manner providing a faster, more efficient and more economical method and apparatus.

A still further object of the invention is to provide an improved code element identification method and apparatus generating, receiving and identifying encoded signals without the necessity of utilizing storage elements, in one form.

Another object of the invention is to provide an improved code element identification method and apparatus capable of generating a substantially large number of distinct codes uniquely identifying each of a substantially large number of code elements in a more efficient and more economical manner.

One other object of the invention is to provide an improved code element identification apparatus controllingly providing access to secured areas in a more efficient, faster and more economical manner.

Another object of the invention is to provide an improved code element identification method and apparatus wherein the predetermined code of the code element is virtually not decipherable via physical inspection of the code element or the measuring of contact resistance or the measuring of the code element inductance or capacitance or the like at predetermined spacially oriented positions.

A still further object of the invention is to provide an improved code element identification method and apparatus which is more economical, reliable and more efficient in the construction and the operation thereof.

Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic, schematic view showing the code element identification apparatus of the present invention.

FIG. 2 is a diagrammatic, schematic view of one preferred embodiment of a code element identification apparatus showing the code element inserted in a code identifying position in the code identifier assembly.

FIG. 3 is a diagrammatic, schematic view showing one preferred embodiment of a code identifier decoder utilized in the code element identification apparatus of FIG. 2.

FIG. 4 is a diagrammatic, schematic view showing one preferred embodiment of an activator utilized to activate the code identifier assembly of the present invention.

FIG. 5 is a diagrammatic, schematic view showing a modified code element assembly.

FIG. 6 is a diagrammatic, schematic view showing one operational embodiment of the code element identification method and apparatus of the present invention for providing access to a predetermined secured area.

FIG. 7 is a diagrammatic, schematic view showing one preferred embodiment of a binary encoder module for emitting an output signal encoded with a predetermined code.

DESCRIPTION OF TI-IE PREFERRED EMBODIMENTS Referring to the drawings in general and to FIG. I in particular, shown therein and designated by the general reference numeral 10 is a code element identification apparatus basically comprising: a code element assembly l2 and an identifier assembly 14. In general, the code element assembly 12 is constructed to receive an interrogate signal 16 and emit a time oriented encoded responder signal 18in response to the received interrogate signal, the responder signal 18 being encoded with a predetermined code element code uniquely identifying the code element assembly 12. The identifier assembly 14 has encoded therein an identifier code and is constructed to generate the interrogate signal 16 and to receive the responder signal 18, in an activated position of the identifier assembly 14 and in a code identifying position of the code element assembly 12 and the identifier assembly 14. The identifier assembly 14 compares the received code element code encoded in the responder signal 18 and the identifier code encoded in the identifier assembly 14 and generates a code valid signal 20 in response to a code element code identically corresponding to the identifier code and generates a foreign code signal 22 in response to a difference between the code element code and the identifier code, the code valid signal 20 and the foreign code signal 22 each being utilized to activate other assemblies and components in a manner to be made more apparent below.

As shown in FIG. 1, the identifier assembly 14, more particularly, includes: an activator 24; a code identifier assembly 26; an identified code element output indicator 28; and an unidentified code element output indicator 30. The activator 24 has an off position and an on position, the activator 24 connecting an activate signal 25 to the code identifier assembly 26 positioning the code identifier assembly 26 in an activated position in response to the received activate signal 25 in an on position of the activator 24. The activator 24, more particularly, connects an operating power supply to the code element assembly 12 and to the identifier assembly 14 in a code identifying position of the code element identification apparatus 10, for reasons and in a manner to be mademore apparent below.

The code identifier assembly 26 has an on position and an activated position, the code identifier assembly 26 receiving the activate signal 25 from the activator 24 and being positioned in the activated position in response thereto. In the activated position of the code identifier assembly 26, the code identifier assembly26 generates the interrogate signal 16 and is positioned to receive the responder signal 18. from the code element assembly 12. The code identifier assembly 26 compares the received code element code encoded in the responder signal 18 with a predetermined identifier code encoded in the code identifier assembly 26 and emits the code valid signal 20 and the foreign code signal 22 in response to the comparison therebetween, as generally referred to before.

The identified code element output indicator 28 is constructed to receive the code valid signal 20 from the code identifier assembly 26 and provide an output indication responsive to a code element code identically compared with the identifier code via the code identifier assembly 26. The unidentified code element output indicator 30 is constructed to receive the foreign code signal 22 from the code identifier assembly 26 indicating a received code element code which does not compare or, in other words, which is not identical to an identifier code and to provide an output indication responsive thereto and indicative thereof.

In a preferred form, as generally indicated in FIG. 1, the code element assembly 12, the activator 24 and the code identifier assembly 26 are each constructed such that the code element assembly 12 must bepositioned in predetermined mechanical proximity with the code identifier assembly 26 (the mechanical proximity being indicated via the dashed-lines in FIG. 1) before the activator 24 will be positioned in the on" position. In one preferred embodiment, the positioning of the code element assembly 12 in the predetermined mechanical proximity with the code identifier assembly 26 positions the activator 24 in the 011" position and positions the code element identification apparatus in the code identifying position, in a manner and forreasons to be made more apparent below.

The identifier assembly 14 of the present invention is particularly constructed to be utilized in cooperation with a code element assembly 12 functioning in the nature of a credit card encoded with a particular code element code identifying the owner of the code element assembly 12 to whome credit is extended, in one operational embodiment of the invention, and functioning in the nature of a key, in one other operational embodiment, for gaining access to a secured area such as via a security gate of a fenced-in area, a door or window or the like of a manufacturing plant, vault or home or the like, and a time clock-like apparatus in yet another operational embodiment, for activation by an employee having a predetermined code element assembly 12 to indicate that the employee has started work, or

for gaining access to a particular machine or, in other identify code element assemblies 12 and activate output indications providing access to the secured area, in one position, and output indications indicating that an unidentified code element code has been recognized via the identifier assembly 14 such as via an audible alarm type of signal or a visually perceivable lamp indicator type of signal or connected to a central security system or the like indicating that the identifier assembly 14 has received and recognized an unidentified or unauthorized code element code, in a manner and for reasons to be described in greater detail below.

The term time oriented is utilized herein to distinguish the type of code generated or emitted via the code element assembly 12 and the identifier assembly 14 of the present invention with respect to code element identification apparatus utilizing a type of spacial orientation for determining the particular code generated, such as via a plurality of electrical conducting paths completing predetermined circuits, a plurality of spacially oriented electrical contacts mating with predetermined spacially oriented electrical contacts, or spacially oriented resistance or inductance elements establishing or completing predetermined control circuits or the like, for example. The term code element" is utilized herein to designate a device constructed to generate or emit a predetermined code such as time oriented binary coded pulses, for example, and functioning in the nature of a key of a key-lock type of security system or a credit card or the like, for example, the code uniquelyidentifying the particular code element and distinguishing that code element with respect to other similarly constructed code elements encoded with different code element codes.

Shown in FIGS. 2 and 3 is one preferred embodiment of a code element identification apparatus, generally designated in FIG. 2 via the reference numeral 100, constructed in accordance with the present invention. The code element identification apparatus 10a includes a code element assembly 12a and an identifier assembly 14a, the code element 12a being shown in mechanical proximity with respect to the identifier assembly 14a and the code element assembly 12a and the identifier assembly each being shown in a code identifying position.

The code element assembly 12a, more particularly, includes a code element 32 generally formed similar to a key or the like having a key head portion 34 and a key insert portion 36, the key insert portion 36 being insertable into a mating, cooperating portion of the identifier assembly 14a in a code identifying position of the code identifying apparatus 10a. A pair of power contacts 38 and 40, a signal receiving contact 42 and a signal emitting contact 44 are each formed on a portion of the key insert portion 36 of the code element 32. The power contacts 38 and 40, the signal receiving contact 42 and the signal emitting contact 44 are each formed of an electrically conductive material and each is connected to a predetermined portion of a code element encoder 46 via a signal path constructed of an electrically conductive material, the signal paths connecting the power contacts 38 and 40 to the code element encoder 46 being designated in FIG. 2 via the reference numerals 48 and 50, respectively, the signal path connecting the signal receiving contact 42 to the code element en coder 46 being designated in FIG. 2 via the reference numeral 52, and the signal path connecting the signal emitting contact 44 to the code element encoder 46 being designated in FIG. 2 via the reference numeral The code element encoder 46 is constructed to generate and transmit the responder signal 18 encoded with the predetermined code element code via the signal path 54 and the signal emitting contact 44 connected thereto when the code element encoder 46 is connected to an operating power supply via the signal paths 48 and 50 connected to the power contacts 38 and 40 in response to a received interrogate signal 16 connected to the code element encoder 46 via the signal receiving contact 42 and the signal path 52. More particularly, the code element encoder 46 is constructed to emitthe encoded responder signal 18 in such a manner'that the predetermined code element code is encoded in the responder signal 18 in a time oriented manner providing a time oriented encoded responder signal 18, as described before. For example, the code element encoder 46, in one form, is constructed utilizing what is generally referred to in the art as a single medium or large scale integrated circuit containing the required circuitry forming a binary encoder module of the type commercially available from such manufacturers as Texas Instruments, lnc. of Dallas, Texas, and sold under their part number designations SN7493 and SN74150, for example, this type of binary encoder being constructed to encipheror effect a conversion of a received signal to a binary code form when connected to an operating power supply and in response to a received signal of a predetermined frequency. The'code element encoder 46 thus provides a responder signal 18 encoded with a predetermined serial binary code, a time oriented code, having a code length equal to the number of bits in the binary encoder module, the predetermined binary code corresponding to the predetermined code element code of the code element encoder 46.

The code element encoder 46 of the present invention is thus small in size (the diagrammatic view of the code element encoder 46 is shown in the drawings'in an enlarged form for the purpose of clarity) and constructed such that it can be secured in the code element 32 in a relatively simple and efficient manner and in a manner making the code element encoder 46 virtually undetactable via visual inspection of the coded element 32. Further, since the code element encoder 46 is of the single integrated circuit type of binary encoder module having a single contact for emitting or transmitting the code element code in lieu of multiple, spacially oriented code forming elements such as conductor paths, electrical resistance or inductance devices or the like, for example, it is virtually impossible to decipher the code element code via visual inspection of the code element 32 or by a simple electrical test such as contact resistance or inductance measurements or the like.

Further, utilizing a code element encoder 46 of the type described above, a substantially large number of binary code element codes can be incorporated in the code element32 without changing the basic design of the code element 32 or the structural shape of the code element 32 or portions thereof such as required when utilizing a large number of contacts to establish the identifying code of the key portion of an identifier assembly. For example, when the code element encoder 46 is constructed of the binary encoder module type generally described above, having 32 bits available to form the code element code, a number equal to 2 (approximately 4 billion) separate, distinct code designations are available for uniquely identifying the code elements 32. However, in each instance, a single contact, the single signal emitting contact 44, is the only contact required to transmit the code element code from the code element 32 to the identifier assembly 14, noting that the power supply and the interrogate signal 16 are also connected to the code element 32.

The activator 24a and the code identifier assembly 26a of the identifier assembly 14a are housed and supported in an identifier support 56, the identified code element output indicator 28 and the unidentified code element output indicator 30 not being shown in FIG. 2 connected to the code valid signal 20 and the foreign code signal 22. A code elementreceiving opening 58 is formed in a portion of the identifier housing 56, the code element receiving opening 58 being shaped to re: ceive the key insert portion 36 of the code element 32 for placing the code element 32 and the identifier assembly 14a in the predetermined mechanical proximity positioning the code element assembly 12a and the identifier assembly 14a in the code identifying position (the key insert portion 36 of the code element 32 being shown inserted in the code element receiving opening 58 and positioned in the mechanical proximity positioning the code element assembly 12a and the identifier assembly 140 in the code identifying position in FIG. 2).

A pair of power contacts 60 and 62 (sometimes referred to herein as the identifier power contacts 60 and 62) are positioned and supported in the code element receiving opening 58 of the identifier support 56 such that the power contacts 60 and 62 contactingly engage the power contacts 38 and 40 of the code element 32 and establish electrical continuity therebetween in a codeidentifying position of the code element identification apparatus l0a. A signal transmitting contact 64 is positioned and supported in the code element receiving opening 58 of the identifier support 56 contactingly engaging the signal receiving contact 42 of the code element 32 establishing electrical continuity therebetween in a code identifying position of the code element identification apparatus 10a. A signal receiving contact 66 is positioned and supported in a portion of the code element receiving opening 58 of the identifier support 56 contactingly engaging and establishing electrical communication with the signal emitting contact 44 of the code element 32 in a code identifying position of the code element identification apparatus 10a.

The code identifier assembly 26a includes a code identifier decoder 70 and a power supply 72. The power supply 72 provides the operating electrical power supply for the code element assembly 12a and the identifier assembly 14a and is connected to the code identifier decoder 70 via a power signal 74 and to the identifier power contacts 60 and 62 via power signals 76 and 78, respectively. The activator 24a is interposed between the power supply 72 and the code identifier decoder 70 and between the power supply 72 and the identifier power contacts 60 and 62, the activator 24a being constructed to establish electrical communication between the power supply 72 and the code identifier decoder 70 and to establish electrical communication between the power supply 72 and the identifier power contacts 60 and 62 in the on position of the activator 24a. The activator 24a, as shown in FIG. 2, is

also constructed such that a portion thereof is supported and disposed within a portion of the code element receiving opening 58 of the identifier support 56, the activator 24a and the key insert portion 36 of the code element 32 each being constructed such that a portion of the activator 24a is mechanically engaged via a portion of the key insert portion 36 positioning the activator 24a in the on position positioning the code element identification apparatus a in the code identifying position, in one preferred form.

The code identifier decoder 70 is constructed to generate and transmit the interrogate signal 16 via a signal path 80 connected between the code identifier decoder 70 and the signal transmitting contact 64 of the identifier assembly 14a and to receive the responder signal 18 connected to the signal receiving contact 66 via a signal path 82 connected between the signal receiving contact 66 and the code identifier decoder 70 in the on or activated position of the code identifier decoder 70. The identifier power contacts 60 and 62, the signal transmitting contact 64, the signal receiving contact 66 and the signal paths, 68, 74, 76, 78, 80 and 82 of the identifier assembly 14a are each constructed of an electrically conductive material in a manner similar to that described before with respect to the power contacts 38 and 40, the signal receiving contact 42, the signal emitting contact 44 and the various signal paths of the code element 32.

In one preferred form, the code identifier decoder, more particularly, includes: a code identifier encoder 84 having an off and an activated position, a clock assembly 86, a pulse counter 88 and a comparator 89 or, more particularly, an exclusive OR gate 90. The clock assembly 86 has an on or activated position and an of position, and is constructed to emit a clock signal 92 having a predetermined frequency in the on position thereof, such clock assemblies being well-known in the art and commercially available from such manufacturers as Texas Instruments, Inc. (SN7400), for example. The clock signal 92 is connected to the code identifier encoder 84 and to the pulse counter 88, the clock signal 92 also providing the interrogate signal 16, as diagrammatically indicated in FIG. 3. The power supply 72 is connected to the code identifier encoder 84, the clock assembly 86, the pulse counter 88 and the exclusive 'OR" gate 90 via the power signal 74, as shown in FIG. 3.

The code identifier encoder 84 has encoded therein the predetermined identifier code and is constructed to generate an output signal 94 having the identifier code encoded therein, in a manner similar to that described before with respect to the code element encoder 46. More particularly, the codeidentification encoder 84 is, in a preferred form, of the binary encoder type commercially available from such companies as Texas Instruments, Inc. of Dallas, Texas, for example, the code identifier encoder 84 emitting the code identifier encoder output signal 94 in response to a received clock signal 92 and a received power signal 74. Thus, in a preferred form, the code identifier encoder 84 and the code element encoder 46 are identical with respect to the overall construction thereof and constructed in a manner eliminating the requirement of having various storage elements located in the identifier assembly 14a.

The code identifier encoder output signal 94 is connected to the input of the exclusive OR gate 90 and the responder signal 18 generated and emitted via the code element encoder 46 is also connected to the input of the exclusive OR" gate 90, as shown in FIG. 3. The exclusive OR" gate 90 is constructed such that an output signal 96 therefrom is in the logical low position when the received code identifier encoder output signal 94 and the received responder signal 18 are identical indicating that the identifier code corresponds identically to the code element code and such that the output signal 96 is positioned in the logical high position in response to a difference between the identifier code and the code element code, the OR" gate output signal 96 being, more particularly, positioned in the logical high position in response to a difference between one bit of the identifier code compared to the corresponding bit of the code element code.

The output signal 96 of the exclusive OR gate 90 is connected to the pulse counter 88, the pluse counter 88 being, more particularly, constructed to receive the OR gate output signal 96 and to be reset in response to a received OR gate signal 96 in the logical high position thereof. As shown in FIG. 3, the output signal 96 of the exclusive OR gate 90 also provides the foreign code signal 22 of the identifier assembly 14a.

The pulse counter 88 is, more particularly, of the digital pulse counter type and is constructed to be positioned in an on position when the power signal 74 is connected thereto and in response to a received clock signal 92, the pulse counter 88 counting a predetermined number of clock signal 92 pulses and generating a pulse counter output signal in response to the received predetermined number of clock signal 92 input pulses. The pulse counter 88 output signal, more particularly, provides the code valid signal 20 of the identifier assembly 14a.

Thus, if the pulse counter 88 counts the predetermined number of clock signal 92 input pulses before being reset via the OR gate output signal 96 the pulse counter emits the code valid signal 20. If the pulse counter 88 is reset via the OR" gate output signal 96 before counting the predetermined number of clock signal 92 input pulses, the pulse counter 88 is reset. Since the OR gate output signal 96 is positioned in the logical low position in response to identically compared bits of the received identifier code and the code element code and, further, since the code element encoder 46, the pulse counter 88 and the code identifier encoder 84 are each operated in response to the received clock signal 92, each count of the pulse counter 88 indicates identically compared corresponding bits encoded in the code identifier encoder output signal 94 and encoded in the responder signal 18.

Operation of FIGS. 1, 2 and 3 The code element identification apparatus 10a of FIGS. 2 and 3 will operate in a manner similar to the code element identification apparatus 10, shown in FIG. 1, described before. In the initial position of the identifier assembly 14a prior to the insertion of the code element 32 in the code element receiving opening 58, electrical communication between the power supply 72 and the identifier power contacts 60 and 62 and between the power supply 72 and the code identifier decoder is interrupted, thereby positioning the code identifier decoder 70 in the off position. Prior to the positioning of the code element 32 in a code identifying position with respect to the identifier assembly 14a, the code element encoder 46 is also positioned in the off position, since operating power is not connected to the power contacts 38 and 40 thereof and an interrogate signal is not connected at the signal receiving contact 42 thereof.

To activate and position the code element identification apparatus a in-a code identifying position, the key insert portion 36 of the code element 32 is inserted in the code receiving opening 58 of the identifier support 56 to a position wherein a portion of the key insert portion 36 engages and mechanically contacts a portion of the activator 24a positioning the activator 24a in the on position connecting the power supply 72 to the identifier power contacts 60 and 62 and to the code identifier decoder 70 via the power signal paths 74, 76 and 78. In the code identifying position of the code element 32 and the identifier unit 14a, the power contacts 38 and 40 of the code element 32 contactingly engage the identifier power contacts 60 and 62 connecting the power supply 72 to the code element encoder 46 of the code element 32 via the power signals 76 and 78, the signal paths 48 and 50, the engaged power contacts 38 and 60 and the engaged power contacts 40 and 62. Further, in the code identifying position of the code element 32 and the identifier assembly 14a, the signal receiving contact 42 of the code element 32 contactingly engages the signal transmitting contact 64 of the identifier unit 14a establishing electrical continuity therebetween and connecting the interrogate signal 16 to the code element encoder 46 of the code element 32 via the signal path 80, the signal transmitting contact 64, the signal receiving contact 42 and the signal path 52. Still further, in the code identifying position of the code element identification apparatus 100, the signal emit ting contact 44 of the key element 32 contactinglyengages the signal receiving contact 66 of the identifier unit 14a establishing electrical continuity therebetween connecting the responder signal 18 to the code identifier decoder 70 via the signal path 54, the signal emitting contact 44, the signal receiving contact 66 and the signal path 82.

In the code identifying position of the code element identification apparatus 10a, the operating power supply provided via the power supply 72 is connected to the code element encoder 46 of the code element32 and to the code identifier encoder 84, the clock assembly 86, the pulse counter 88 and the exclusive OR gate 90 of the code identifier decoder 70. In this position, the clock assembly 86 is positioned in the on or activated position generating and emitting the clock signal 92, the clock signal 92 being the interrogate signal 16, in one form, as shown in FIG. 3. The interrogate signal 16 is connected to the code element encoder 46 clock signal 92, the code identifier encoder output signal 94 and the responder signal 70 are synchronized with respect to time and each is connected to the input of the exclusive OR gate 90. Each bit of the identifier code is thus compared with each corresponding bit of the code element code encoded in the responder signal 18 via the exclusive OR gate 90. Further, the pulse counter 88 receives the clock signal 92 and counts the clock signal 92 pulses, the pulse counter 88 providing the code valid signal 20 in response to a predetermined number of clock signal 92 input pulses counted via the pulse counter 88 indicating a corresponding number of bits in the identifier code and the code element code have been compared and determined to be identical via the comparator 89. Since the pulse counter 88 also receives and operates in response to the clock signal 92, the operation of the pulse counter 88 is synchronized with the operation of the code element encoder 46 and the code identifier encoder 84. During the operation of the code element identification apparatus 10a, should any one bit of the identifier code not compare identically to the received code element code as determined via the comparator 89, the output signal 96 of the comparator'89 will be positioned in the high position resetting the pulse counter 88 and generating the foreign code signal 22 activating the unidentified code element output indicator 30.

Embodiment of FIG. 4

Shown diagrammatically and schematically in FIG. 4 is one preferred form of an activator 24b constructed to establish electrical communication between a power supply 72b and the power contacts and 62 and the code identifier decoder of the code element identification apparatus lOa, in a manner similar to that described before with respect to the activator 24a, shown in FIGS. 1 and 2.

andthe code element encoder 46 emits the responder signal 18 encoded with the predetermined code element code connected to and received via the exclusive OR gate of the code identifier decoder 70. The clock signal 92 is also connected to the code identification encoder 84, the code identifier encoder 84 generating and emitting the output signal 94 encoded with the predetermined identifier code in response to the received clock signal 92 when connected to the power supply 72.

Since the code element code is encoded in the responder signal 18 in response to the received interrogate signal 16 corresponding to the clock signal 92 and the identifier code is encoded in the code identifier en- The activator 24b, shown in FIG. 4, more particularly, connects a battery type of power supply 100 to the power contacts 60 and 62 and to the code identifier decoder 70 via a switch 101 having switch arm 102 cooperating with a contact 104, the switch arm 102 and the contact 104 establishing electrical continuity therebetween positioning the activator 24b in the on position when the switch arm 102 is moved into engagement with the contact 104. A switch plunger 106 is reciprocatingly disposed through a switch opening 108 formed in the identifier support 56b intersecting a portion of the code element receiving opening 58b and a switch bias spring 110 engages a portion of the switch plunger 106 and a portion of the identifier support 56b biasing the switch plunger 106 generally away from the switch arm 102 breaking the contact between the switch arm 102 and the contact 104 and positioning the activator 24b in the off position.

The switch plunger 106 is supportedly positioned within the code element receiving opening 58b such that a portion of the code element assembly 12 contactcoder output signal 94 in response to the received ingly engages the switch plunger 106 and moves the switch plunger 106 against the biasing force of the switch bias spring 110 thereby moving the switch plunger 106 into contacting engagement with the switch arm 102, the switch arm 102 being moved to establish electrical continuity between the switch arm 102 and the contact 104 positioning the activator 24b in the on position. The switch bias spring 110 thus maintains the identifier assembly 14a or the like in an off position until the switch plunger 106 is mechanically engaged via a portion of the code element assembly l2.

Embodiment of FIG.

Shown in FIG. 5 is a modified code element 320, constructed similar to the code element 32, shown in FIG. 2 and described in detail before, the salient difference being that the modified code element 320 includes a card element 111 having a basically rectangular shape in lieu of the key-shaped code element 32, shown in FIG. 2, including the key head portion 34 and the'key insert portion 36. The card element 111 has a code element encoder 460 secured to a portion thereof, the code element encoder 46c being constructed similar to the code element encoder 46, described before, and connected to power contacts 38c and 40c via the signal paths 48c and 500, respectively, and to the signal receiving contact 42c and the signal emitting contact 440 via signal paths 52c and 540, respectively, as shown in FIG. 5.

The code element 32c having a card-shaped form comprising the card element 111 will function and operate in a manner similar to that described before with respect to the code element 32 for receiving interrogate signals and emitting responder signals encoded with a predetermined code element code for identification via an identifier assembly constructed similar to the identifier assembly 140 of FIGS. 2 and 3, the contacts, 380, 40c, 42c and 44c being positioned on the card element 111 for engagement with the contacts 60, 62, 64 and 66, respectively, of the identifier assembly 14a, and a portion of the card element 111 engaging and mechanically contacting the activator 24a positioning the activator 24a in the on" position in a manner similar to that described before with respect to the key-shaped code element 32 and the identifier assembly 14a. Thus, the code element assembly 12c retains substantially all of the advantages of the code element identification apparatus 10a and yet provides a code element 32cconstructed in the form of a card to be utilized in the nature of a credit cardor other similar type of identification card or the like. It should benoted that, in one other form (not shown), thecontacts 38c, 40c, 42c and 440 are formed or secured on opposite faces of the card element 111 in lieu of being positioned on opposites sides as shown in FIG. 5.

Embodiment of FIG. 6

locked position and a release position, the lock as-,

sembly 28d having a door bolt portion 116 extending from the door 112 through a portion of the door frame 114 or, in other words, engaging a portion of the entrance boltingly securing the door 112 in a closed position in a locked" position of the lock assembly 28d to substantially prevent access to the secured area. The lock assembly 28d is also constructed such that the door bolt portion 116 is retracted releasing the engagement between the lock assembly 28d and the entrance in a release position of the lock assembly 28d, the door 112 being openable via a doorknob 118 in the conventional manner in response to an identified valid code element code.

The lock assembly 28d is, more particularly, constructed to receive the code valid signal 20, the lock assembly 28d being positioned in the release" position in response to the received code valid signal 20 indicating that a code element assembly has been inserted in the code element receiving opening 58 and positioned in a code identifying position with respect to a code identifier assembly 26 and the code element assembly '(not shown in FIG. 6) has emitted a responder signal 18 encoded with a code element code identified via the code identifier assembly 26. Thus, in this operational embodiment of the invention, the output indication of the identified code element output indicator 28d is, more particularly, the unlocking of the door 112 to provide access to an area secured thereby. The door bolt portion 116 of the lock assembly 28d, in one form, can be constructed to be operated via a solenoid actuator, the solenoid being energized and de-energized via the code valid signal 20 generated and emitted via the code identifier assembly 26, this type of construction being well-known in the art.

The unidentified code element output indicator 30d is, more particularly, an alarm constructed to receive the foreign code signal 22 and produce an audible alarm signal in response thereto indicating that a code element assembly 12 has been positioned within the code element receiving opening 58 in a code identifying position and that the code element code encoded in the responder signal 16 has been determined not to correspond to the identifier code.

The code element identifier apparatus 10d secured in the door 112 and operating in cooperation with the door frame 114 to secure the door in a locked" and a release position will operate in a manner substantially similar to the code element identification apparatus described before. The code element receiving opening 58 is formed through a portion of the door 112, the

activator 24a being positioned for mechanical, contacting engagement via the code element such as the code element 32 (shown in FIG. 2) or the code element 320 (shown in FIG. 5). In the embodiment of the invention shown in FIG. 6, the code identifier assembly 26, the

lock assembly 28d and the alarm 30d are each diagrammatically and schematically shown as being supported and securedly positioned within a portion of the door 112; however, it should be particularly noted that the code element identification apparatus 10d can also be located in a portion of the structure associated with the door frame 114, the door bolt portion 116 extending through the door frame 114 and through a portion of the door 112 in this alternate embodiment of the invention (not shown). Further, it should be noted that only the code identifier encoder 84 need be changed to provide a different, predetermined identifier code to change a particular code element identification apparatus 10d to cooperate with a code element having a different code element code, thereby providing a practical apparatus facilitating the change of locks in those instances where a particular code element has been lost or stolen.

Embodiment of FIG. 7

Asmentioned before, the code element encoder 46 and 46c and the code identifier encoder 84 are each binary encoder modules and, in a preferred form, are constructedstructurally similar. Shown in FIG. 7 is one preferred embodiment of a binary encoder module 120 constructed to emit a responder signal 18 in response to a received interrogate signal 16 when an operating power supply is connected thereto, and constructed to emit the output signal 94 of the code identifier encoder 84 in response to the received clock signal 92 when an operating power supply is connected thereto. More particularly, the binary encoder module 120 is of the integrated circuit family and includes: a power supply terminal 122, a ground terminal 124, a program terminal 126, a signal receiving terminal 128 and a signal emitting terminal 130, the terminals 122 through 130 comprising the external terminal connections of the binary encoder module 120. The binary encoder module 120, shown in FIG. 7, is constructed to receive a signal at the signal receiving terminal l28and to encode a predetermined binary code therein generating and emitting a signal at the signal emitting terminal 130 encoded with the predetermined code.

The power supply terminal 122 is connected to a pulse generator 132 via a resistor 134 and a time delay network 136 comprising a resistor 138 and a capacitor 140 connected in parallel, the time delay network 136 being constructed to delay a power signal connected to the power supply terminal 122 for a predetermined period of time to assure that all of the counters of the binary encoder module 120 have been set to zero prior to receiving a signal connected at the signal receiving terminal 128 and connecting that signal to a counter 142. Utilizing the binary encoder module 120 for the code element encoder 46 and the code identifier encoder 84, the time delay network 136 cooperates to assure that the responder signal 18 and the code identifier encoder output signal 94 received at the comparator 89 (shown in FIG. 3) are synchronized.

The circuits of the pulse generator 132 are each, more particularly, of the type generally known in the art as a retriggerable one shot multivibrator which is constructedtto be triggered when the voltage level received from the power supply terminal 122 via the time delay network 136 has reached a predetermined voltage level or, in other words, after a predetermined time delay, the pulse generator 132 providing a power output signal 144 in response to a received input signal at the predetermined voltage level. A retriggerable one shot multivibrator constructed to operate in a manner generally described before with respect to the pulse generator 132 is commercially available from such manufacturers as Texas Instruments, Inc. of Dallas, Texas, and soldunder the Texas Instruments, Inc. part number designation SN54l2l, for example.

In a preferred form, the circuits of the counter 142 is, more particularly, of the type generally referred to in the art as a four-bit binary counter sequentially providing four output signals or signal states 150, 152, 154 and 156 in response to received input signal pulses connected thereto via the signal receiving terminal 128, each output signal 150-156 corresponding to a predetermined number of electrical pulses of the input signal connected to the counter 142, via the signal receiving terminal 128.

The fourth order output signal 156 of the counter 142 is connected to the input of a counter 158, the counter 158 being of the type generally referred to in the art as a four-bit type of counter, similar to the counter 142, providing four output signals 160, 162, 164 and 166 in response to the received input signal 156. Thus, the counter 158 receives an input pulse for every sixteen pulses of the signal connected at the signal receiving terminal 128 and sequentially provides the output signals 160, 162, 164 and 166 in response thereto. The fourth order output signal 166 of the counter 158 is connected to a counter 168, the counter 168 being constructed similar to the counters 142 and 158 but,.more particularly, sequentially providing two output signals 160 and 172 in response to the received input signal 166 connected thereto. In other words, the counter 168 is, in essence, one-half of the digital counters utilized as the counters 142 and 158, commonly referred to as a two bit counter.

The operating power supply provided via the pulse generator 132 and, more particularly, the power output signal 144 therefrom is connected to each of the counters 142, 158 and 160 providing the operating power supply therefor. Counters constructed to operate in a manner similar to that described before with respect to the counters 142 and 158 are commercially available from such manufacturers as Texas Instruments, Inc. of Dallas, Texas, such as the type sold under the Texas Instruments, Inc. part number designation SN5493, for example, the counter 168 being constructed in a similar manner and also commercially available from such manufacturers as Texas Instruments, Inc. of Dallas Texas, for example.

The binary encoder module includes circuits equivalent in operation to sixty-four identical sixteen bit encoders 174, only the first encoder 174A and the last encoder 174B being shown in FIG. 7 for the purpose of. clarity of description and the dashed-line connecting the first encoder 174A and the last or sixtyfourth encoder 174B being utilized to designate the additional sixty-two encoders 174 therebetween. Each of the encoders 174 is connected and operates in a manner identical to that described below with respect to the first encoder 174A and the last encoder 174B and therefore a detailed description of the various connections of the intervening 62 encoders (not shown in FIG. 7) is not required herein and will be apparent to those skilled in the art from the detailed description of the connection and operation of the first and the last encoders 174A and 1748 herein.

The four output signals 150, 152, 154 and 156 of the counter 142 are each connected in parallel to each of the sixty-four encoders 174, as shown in FIG. 7 with respect to the first and the last encoder 174A and 174B. Each of the sixty-four encoders 174 is constructed to receive the four input signals 150, 152, 154 and 156 and provide a predetermined number of bit output signals 176 indicative of a logical high (logical one) or a logical low (logical zero) in accordance with a predetermined code encoded in each of the sixty-four encoders 174, the output signals provided via the first encoder 174A being shown in FIG. 7 and designated therein by the reference numeral 176A and the output signals provided via the last encoder 174B being shown in FIG. 7 and designated therein by the reference numeral 176B. The dashed-lines between the two encoder output signals 176A and 176B being shown in FIG. 7

to diagrammatically illustrate the presence of 62 additional encoder output signals 176 generated via the encoders 174 in response to the received counter 142 output signals 150 through 156 in an enabled position of the encoders 174. g

The sixty-four output signals 176 are each connected to the input of an OR gate 180, the OR gate 180 providing an output signal 182 in response to the received encoder output signals 176. The OR gate output signal 182 is connected to the signal emitting terminal 130, the OR gate output signal 182 providing the encoded output signal of the binary encoder module 120.

Each of the sixty-four encoders 174 has an off position and an enabled position and each of the sixtyfour encoders 174 is, more particularly, constructed to provide the particular encoder output signals 176 in an enabled position of the encoder 174. Thus, each of the sixty-four encoders 174 receives an enable signal generated via an encoder enable assembly 183, the sixtyfour enable signals being generally designated in FIG. 7 via the reference numeral 184 and the dashed-lines connecting the first enable signal 184A and the sixtyfourth enable signal 1848 representing the additional sixty-two enable signals 184 not specifically shown in FIG. 7. The first enable signal 184A from the encoder enable assembly 183 is connected to the first encoder 174A and the sixty-fourth enable signal 1848 is connected to the sixty-fourth encoder 1748, the sixty-two enable signals 184 between the first and the last enable signals 184A and 1848 each being connected to one of the sixty-two encoders 174 between the first encoder 174A and the sixty-fourth encoder 174B and each enable signal 184 positioning the encoder 174 connected thereto in the enabled position.

Thus, the encoder enable assembly 183 receives the six input signals 160, 162, 164, 166, 170 and 172 from the counters 158 and 168 and provides sixty-four output signals 184, each output signal 184 being connected to one of the encoders 174 positioning the encoder 174 connected thereto in the enabled position for a predetermined period of time sufficient for the enabled encoder 174 to produce the sixteen-bit code encoded therein. Further, each output signal 184 of the encoder enable assembly 183 sequentially provides the enabling output signals 184 to sequentially enable each of the encoders 174 in accordance with a predetermined program. Encoder enable assemblies constructed to operate in a manner similar to that described above with respect to the encoder enable assembly 183 are commercially available from such manufacturers as Texas Instruments, Inc. of Dallas, Texas, for example, and generally referred to in the art as "6 Bit By 64 Select Matrix", the encoder enable assembly being typically constructed utilizing four commercially available elements each identified by the part number designation SN54154 of Texas Instruments. Inc.. for example.

In one preferred form, each of the sixty-four encoders 174 is constructed to receive the counter 142 output signals I50, 152, 154 and 156 and provide a sixteen-bit code in accordance with a predetermined code program encoded in the encoders 174 in an enabled position of the encoders 174, the sixteen-bit code output signal of each of the encoders 174 being connected to the OR gate 180 via one of the encoder signals 176, as generally described before. Further, each of the sixty-four encoders 174 is constructed and connected in the integrated circuit,shown in FIG. 7, such that the predetermined sixteen-bit code can be permanently programmed in each encoder 174 via a program network 186, an identical program network 186 being connected to each of the sixty-four encoders 174 (only the two program networks 186A and 186B connected to the first encoder 174A and the sixty-fourth encoder 1748 being shown in FIG. 7 for the purpose of clarity of description).

Eachv program network 186 includes sixteen gates 188, only the first and the sixteenth gates 188A and 1888 connected to the first encoder 174A and the first and sixteenth gates 188C and 188D connected to the sixty-fourth encoder 1748 being shown in FIG. 7 for the purpose of clarity of description and the dashedlines connecting the first and the sixteenth gates 188A and 188B connected to the first encoder 174A and the dashed-lines connecting the first and the sixteenth gates 188C and 188D connected to the sixty-fourth encoder 174B representing and designating the additional fourteen gates 188 connected to the first and the last encoder 174A and 1743, respectively.

Each of the gates 188 is connected to the ground terminal 124 via a ground line 190, to the program terminal 126 via a program line 192 and to the power supply terminal 122 via a power line 193. Each of the gates 188 is also connected to a gate line 194, each encoder 174 having sixteen gate lines 194 wherein each gate line 194 corresponds to one bit of the sixteen-bit code of the encoder .174 and the dashed-lines between the gate lines 194 shown in FIG. 7 designate the fourteen additional gate lines 194 (not shown in FIG. 7). The first and the sixteenth gate lines 194 are shown in FIG. 7 connected between the first and the sixteenth gates 188 of the first and the sixty-fourth encoders 174A and 174B, the first and the sixteenth gate lines connected to the first encoder 174A being designated in FIG. 7 via the reference numerals 194A and 1948, respectively, and the first and the sixteenth gate lines connected to the sixty-fourth encoder 1748 being designated in FIG. 7 via the reference numerals 194C and 194D, respectively, for the purpose of clarity of description.

Each encoder 174 is also connected to each of the sixteen gates 188 connected thereto via code lines 196, the dashed-lines between the two code lines 196 connected to each of the two encoders 174A and 174B, shown in FIG. 7, representing and designating the fourteen additional code lines 196 connected between each of the encoders 174 and the sixteen gates 188 connected thereto. The first and the sixteenth code lines 196 are shown in FIG. 7 connected between the first and the sixteenth gates 188 of the first and the sixtyfourth encoders 174A and 1748, the first and the sixteenth code lines connected to the first encoder 174A being designated in FIG. 7 via the reference numerals 196A and 196B, respectively, and the first and the sixteenth code lines connected to the sixty-fourth encoder 174B being designated in FIG. 7 via the reference numerals 196C and 196D, respectively, for the purpose of clarity of description.

Each encoder 174 is constructed to be encoded with a predetermined sixteen-bit code when the binary encoder module 120 is positioned in a program position wherein the power supply terminal 122 is connected to a positive power supply, the ground terminal 124 is connected to ground, the program terminal 126 is connected to a program power supply and the signal receiving terminal 128 is connected to a pulse generator apparatus providing a predetermined signal at a controlled rate.

The gates 188 are each constructed such that in the program position of the binary encoder module 120 the code lines 196 of each of the encoders 174 are each sequentially connected to the program terminal 126 via the program line 192 and each bit position of each of the encoders 174 is connected to the program power supply encoding a logical high (logical one) or a logical low (logical zero) at each of sixteen bit positions of each of the encoders 174 as controlled via the predetermined code to be encoded in the binary encoder module 120. A logical low (logical zero) is permanently encoded in a particular bit position when the program power supply is connected to that particular bit position via one of the gates 188 and a logical high (logical one) is permanently encoded in a particular bit position when the program power supply is not connected to that particular bit position via one of the gates 188, the connecting and disconnecting of the program power supply to the bit positions of the encoders 174 via the gates 188 being well-known in the art. After each encoder 174 has been encoded with the predetermined sixteen-bit code, the program voltage source (not shown) connected at the program terminal 126 is activated to fuse or burn the program line 192, sometimes referred to herein as a .destruct signal, thereby leaving each encoder 174 permanently encoded with the predetermined si-xteen-bit code.

After each encoder 174 has been encoded with the predetermined sixteen-bit code, the binary encoder module 120 is then connected and utilized to generate the code element code or identifier code corresponding to the permanently encoded code of the encoders 174, in one form, each encoder 174 providing a portion of the code element code or identifier code. Thus, the binary encoder module 120 is utilized to generate the code element code or the identifier code, for example, and in each instance, the power supply terminal 122 of the binary encoder module 120 is connected to the operating power supply, the ground terminal 124 is connected to ground, the signalreceiving terminal 128 is connected to receive the clock signal 92 generated via the clock assembly 86 and the signal emittingterminal 130 is connected to provide the encoded output signal of the code element encoder or the code identifier encoder, for example.

During the operation of the binary encoder module 120, the encoder enable assembly 183 sequentially enables the encoders 174, each encoder 174 providing a portion of the total code element code or identifier code produced at the signal emitting terminal 130. In the code element identification apparatus of the present invention, the pulse counter 88 (FIG. 3) is set to count a predetermined number of clock signal 92 pulses equal to at least the number of bits in the code permanently encoded in the binary encoder module 120, in a preferred form, and, in one other form, counts a predetermined number of clock signal 92 pulses equal to a multiple of the number .of bits in the code permanently encoded in the binary encoder module 120 thereby allowing the code to be repeated at the signal emitting terminal 130 a predetermined number of times.

Changes may be made in the construction and operation of the various components and assemblies and in the steps of the method described herein without departing from the spirit and scope of the invention as defined in the following claims.

What is claimed is:

1. A code element identification apparatus, comprismg:

code element means receiving an interrogate signal and emitting a time oriented responder signal encoded with a predetermined code uniquely identifying the code element means in response to the received interrogate signal and in an activated position of the code element means; and

identifier means having one portion generating the interrogate signal and one other portion receiving and identifying the responder signal and generating a code valid signal in response to an identified predetermined code encoded in the received responder signal and in an activated position of the identifier means.

2. The apparatus of claim 1 wherein the identifier means includes:

clock means generating a clock signal in an activated position thereof having a predetermined frequency, the clock signal being the interrogate signal received via the code element means;

code identifier encoder means receiving the clock signal and emitting a time oriented output signal encoded with a predetermined identifier code in response to the received clock signal in an activated position thereof, the encoded code identifier encoder means output signal being synchronized relative to the encoded responder signal via the clock signal; and

comparator means receiving the encoded responder signal and the code identifier encoder means output signal and comparing the encoded code element code with the encoded identifier code and providing an output indication responsive thereto in an activated position thereof.

3. The apparatus of claim 2 wherein the identifier means is defined further to include:

means receiving the comparator means output signal and the clock signal and counting the number of identically compared bits of the code element code and the identifier code providing the code valid signal in response to a predetermined number of counted identically compared bits of the code element code and the identifier code.

4. The apparatus of claim 3 wherein the comparator means output signal is low in response to received identically compared bits of the code element code and the identifier code and high in response to a difference between any one of the compared bits of the code element code and the identifier code; and wherein the means counting the identically compared bits includes:

pulse counter means receiving the clock signal and the comparator means output signal and counting the clock signal pulses, the pulse counter means being reset in response to a received high" comparator means output signal and providing the code valid signal in response to a predetermined number of counted clock signal pulses.

5. The apparatus of claim 1 wherein the identifier means is defined further to include:

power supply means providing operating power for activating the code element means and the identifier means when connected thereto; and

means connecting the power supply means to the code element means and the portions of the identifier means generating the interrogate signal and receiving and identifying the responder signal in one position thereof.

6. The apparatus of claim wherein the means connecting the power supply means to the code element means and the identifier means includes:

activator means interposed between the power supply means. and the code element means and between the power supply means and the portion of the identifier means generating the interrogate signal and receiving and identifying the responder signal, having an on and an off" position, the activator means connecting the power supply means to the code element means and the identifier means in the on position thereof; and

means positioning the activator means in the on position in one position thereof.

7. The apparatus of claim 6 wherein the identifier apparatus includes: identifier support means, having a portion receiving a portion of the code element means and a portion supporting a portion of the activator means generally within the portion receiving a portion of the code element means; and wherein the portion of the activator means supported within the portion of the identifier support means receiving a portion of the code element means is engageable via the code element means positioning the activator means in the on position.

8. The apparatus of claim 7 wherein the activator means includes:

switch means interposed between the power supply means and the code element means and between the portions of the identifier means generating the interrogate signal and receiving and identifying the responder signal, having an open position disconnecting the power supply means and a closed position connecting the power supply means positioning the activator in the "on position; and

switch plunger means, having a portion engageable via a portion of the code element means, a portion of the switch plunger means engaging a portion of the switch means positioning theswitch means in a closed position in an engaged position of the switch means and the switch plunger means.

9. The apparatus of claim 5 wherein the identifier means is defined further to include:

signal receiving contact means engageable with a portion of the code element means receiving the responder signal in a code identifying position of the code element means and the identifier means;

signal transmitting contact means engageable with a portion of the code element means, the interrogate signal being connected to the signal transmitting contact means; and

identifier power contact means engageable with a portion of the code element means and connected to the power supply means; and

wherein the code element means is defined further to include:

code element power contact means engaging the identifier contact means in a code identifier position of the code element means and the identifier means connecting the power supply means to and activating the code element means; signal receiving contact means engaging the signal transmitting contact means of the identifier means in a code identifying position of the code element means and the identifier means connecting the interrogate signal to the code element means; and

signal emitting contact means engaging the signal receiving contact means of the identifier means in a code identifying position of the code element means and the identifier means connecting the responder signal to the identifier means.

10. The apparatus of claim 2 wherein the comparator means includes: an exclusive OR gate means receiving the encoded responder signal and the code identifier encoder means output signal providing an output signal in the high" position in response to a difference between any one of the compared bits of the code element code and the identifier code, the OR gate means output signal providing a foreign code signal in the high position thereof indicating a difference between the compared code element code and the identifier code.

11. The identifier apparatus of claim 1 controlling access to a secured area through an entrance or the like defined further to include:

lock assembly means, having a locked and a release position and a portion engageable with a portion of the entrance or the like to substantially prevent access to the secured area via the entrance or the like in a locked position of the lock assembly means, the lock assembly means receiving the code valid signal and being positioned in the release position releasing the engagement between the lock assembly means and the entrance or the like for providing access to the secured area via the entrance or the like.

12. The identifier apparatus of claim 11 wherein the identifier means is defined further to include a portion generating a foreign code signal in response to a responder signal encoded with a code other than the predetermined code generating the code valid signal; and wherein the apparatus is defined further to include: alarm means receiving the foreign code signal and producing an output indication in response thereto.

13. The apparatus of claim 1 wherein the portion of the code element means receiving the interrogate signal and emitting the responder signal in response thereto is defined further to include:

a binary encoder module, comprising: V

a program terminal connectable to a program power supply;

a signal receiving terminal;

a signal emitting terminal;

encoder means connected to the signal receiving terminal, the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetermined code corresponding to the code element code and producing a signal encoded with the predetermined code element code connected to the signal emitting terminal in response to a received input signal receivable at the signal receiving terminal in an enabled position of the encoder means;

means interposed between the encoder means and the program terminal encoding the predetermined code element code in the encoder means in response to a predetermined program power supply receivable at the program terminal, having a fuseable portion destroyable in response to a predetermined destruct signal receivable at the, program terminal, the encoder means being permanently encoded with the code element code in a fused position of the fuseable portion; and means connected to the encoder means sequentially enabling the encoder means producing the signal encoded with the code element code at the signal emitting terminal. 14. The apparatus of claim 13 wherein the portion of the identifier means identifying the received responder signal encoded with the code element code is defined further to include:

a binary encoder module, comprising:

a program terminal connectable to a program power supply; a signal receiving terminal; a signal emitting terminal; encoder means connected to the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetermined code corresponding to the identifier code and producing a signal encoded with the predetermined identifier code connected to the signal emitting terminal in response to an input signal receivable at the signal receiving terminal in an enable position of the encoder means; means interposed between the encoder means and the program terminal encoding the predetermined identifier code in the encoder means in response to a predetermined program power supply receivable at the program terminal, having a fuseable portion destroyable in response to a predetermined destruct signal receivable at the program terminal, the encoder means being pennanently encoded with the identifier code in a fused position of the fuseable portion; and means connected to the encoder meanssequentially enabling the encoder means producing the signal encoded with the identifier code at the signal emitting terminal. 15. Theapparatus of claim 14 wherein the binary encoder modules of the code element means and the identifier means are each defined further to include a plurality of encoder means; and wherein the means enabling the encoder means of the code element means and the identifier means are each further defined as connected to each encoder means sequentially enabling each encoder means producing the signal at the signal emitting terminal, the code encoded in each encoder means forming a portion of the code encoded in the signal at the signal emitting terminal.

16. Apparatus for receiving an interrogate signal and emitting an encoded signal in response thereto when connected to a power supply, comprising:

a code element; power contact means formed on a portion of the code element connectable to the power supply in one position of the code element;

signal receiving contact means formed on a portion of the code element receiving the interrogate signal in one position of the code element;

signal emitting contact means formed on a portion of the code element, the emitted encoded signal being connected to the signal emitting contact means in one position of the code element; code element encoder secured to a portion of the code element, having a portion connected to the power contact means, a portion connected to the signal receiving contact means and a portion connected to the signal emitting contact means, the code element encoder emitting a time oriented encoded responder signal connected to the signal emitting contact means in response to the received interrogate signal at the signal receiving contact means and the power source at the power contact means, the code encoded in the responder signal .uniquely identifying the code element. 17. A method for identifying code elements via an identifier wherein each code element is encoded with a predetermined code element code and each identifier is encoded with an identifier code, comprising:

generating a clock signal having a predetermined frequency;

receiving the clock signal at the code element and generating a time oriented responder signal encoded with the code element code in response thereto;

receiving the clock signal at the identifier and generating a time oriented output signal encoded with the identifier code in response thereto;

receiving and comparing the codes encoded in the responder signal and the identifier output signal; and

producing code valid signal in response to identically compared codes encoded in the responder signal and the identifier signal.

18. The method of claim 17 defined further to include the step of:

positioning the code element in a code identifying position with respect to the identifier connecting a power supply to the code element and the identifier providing operating power therefor.

19. The method of claim 18 wherein the step of positioning the codeelement and the identifier in a code identifying position is further defined as connecting the clock signal to the code element and connecting the responder signal to the identifier.

20. The method of claim 17 further defined to include the step of:

counting the number of identically compared bits of the code element code and the identifier code; and wherein the step of producing the code valid signal is further defined as producing the code valid signal in response to a predetermined number of counted identically compared bits of the code element code and the identifier code.

21. A binary encoder module apparatus, comprising:

a program terminal connectable to a program power pp y;

a signal receiving terminal;

a signal emitting terminal;

encoder means connected to the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetennined code for producing a signal encoded with the predetermined code connected to the signal emitting terminal in response to a signal received at the signal receiving terminal in an enable position of the encoder means;

enabling the encoder means producing the encoded signal at the signal emitting terminal.

22. The apparatus of claim 21 defined further to include a plurality of encoder means; and wherein the means enabling the encoder means is defined further as connected to each encoder means sequentially enabling each encoder means producing the signal at the signal emitting terminal, the code encoded in each encoder means forming a portion of the code encoded in the signal at the signal emitting terminal.

Po-wso UNITED STATES, PATENT OFFICE CERTIFICATE OF CORRECTION 1mm No- 3. ez9 ,s33 m August 13, 1974 Inventr( Charles C. Freeny, Jr,

It is cettified that error eppears 1n the above ide ntified atent' and that said Letters Patent are hereby corrected as shown below Column l line 21, responsie" should be -respons e--. Column line 21 "mechannical" should be mechanical-. Column'Z, line 23, "spaded" should be --spaced--. Column 3 line 9, "reasonate" should be resonate-. Column 5 line 27, "an" should be "the- Column 5, line 50 "whome" should be vhom-.

Column .7, line 45, "undetectable" should be "undetectable-:-

Signed and sealed this 29th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A code element identification apparatus, comprising: code element means receiving an interrogate signal and emitting a time oriented responder signal encoded with a predetermined code uniquely identifying the code element means in response to the received interrogate signal and in an activated position of the code element means; and identifier means having one portion generating the interrogate signal and one other portion receiving and identifying the responder signal and generating a code valid signal in response to an identified predetermined code encoded in the received responder signal and in an activated position of the identifier means.
 2. The apparatus of claim 1 wherein the identifier means includes: clock means generating a clock signal in an activated position thereof having a predetermined frequency, the clock signal being the interrogate signal received via the code element means; code identifier encoder means receiving the clock signal and emitting a time oriented output signal encoded with a predetermined identifier code in response to the received clock signal in an activated position thereof, the encoded code identifier encoder means output signal being synchronized relative to the encoded responder signal via the clock signal; and comparator means receiving the encoded responder signal and the code identifier encoder means output signal and comparing the encoded code element code with the encoded identifier code and providing an output indication responsive thereto in an activated position thereof.
 3. The apparatus of claim 2 wherein the identifier means is defined further to include: means receiving the comparator means output signal and the clock signal and counting the number of identically compared bits of the code element code and the identifier code providing the code valid signal in response to a predetermined number of counted identically compared bits of the code element code and the identifier code.
 4. The apparatus of claim 3 wherein the comparator means output signal is ''''low'''' in response to received identically compared bits of the code element code and the identifier code and ''''high'''' in response to a difference between any one of the compared bits of the code element code and the identifier code; and wherein the means counting the identically compared bits includes: pulse counter means receiving the clock signal and the comparator means output signal and counting the clock signal pulses, the pulse counter means being reset in response to a received ''''high'''' comparator means output signal and providing the code valid signal in response to a predetermined number of counted clock signal pulses.
 5. The apparatus of claim 1 wherein the identifier means is defined further to include: power supply means providing operating power for activating the code element means and the identifier means when connected thereto; and means connecting the power supply means to the code element means and the portions of the identifier means generating the interrogate signal and receiving and identifying the responder signal in one position thereof.
 6. The apparatus of claim 5 wherein the means connecting the power supply means to the code element means and the identifier means includes: activator means interposed between the power supply meAns and the code element means and between the power supply means and the portion of the identifier means generating the interrogate signal and receiving and identifying the responder signal, having an ''''on'''' and an ''''off'''' position, the activator means connecting the power supply means to the code element means and the identifier means in the ''''on'''' position thereof; and means positioning the activator means in the ''''on'''' position in one position thereof.
 7. The apparatus of claim 6 wherein the identifier apparatus includes: identifier support means, having a portion receiving a portion of the code element means and a portion supporting a portion of the activator means generally within the portion receiving a portion of the code element means; and wherein the portion of the activator means supported within the portion of the identifier support means receiving a portion of the code element means is engageable via the code element means positioning the activator means in the ''''on'''' position.
 8. The apparatus of claim 7 wherein the activator means includes: switch means interposed between the power supply means and the code element means and between the portions of the identifier means generating the interrogate signal and receiving and identifying the responder signal, having an open position disconnecting the power supply means and a closed position connecting the power supply means positioning the activator in the ''''on'''' position; and switch plunger means, having a portion engageable via a portion of the code element means, a portion of the switch plunger means engaging a portion of the switch means positioning the switch means in a closed position in an engaged position of the switch means and the switch plunger means.
 9. The apparatus of claim 5 wherein the identifier means is defined further to include: signal receiving contact means engageable with a portion of the code element means receiving the responder signal in a code identifying position of the code element means and the identifier means; signal transmitting contact means engageable with a portion of the code element means, the interrogate signal being connected to the signal transmitting contact means; and identifier power contact means engageable with a portion of the code element means and connected to the power supply means; and wherein the code element means is defined further to include: code element power contact means engaging the identifier contact means in a code identifier position of the code element means and the identifier means connecting the power supply means to and activating the code element means; signal receiving contact means engaging the signal transmitting contact means of the identifier means in a code identifying position of the code element means and the identifier means connecting the interrogate signal to the code element means; and signal emitting contact means engaging the signal receiving contact means of the identifier means in a code identifying position of the code element means and the identifier means connecting the responder signal to the identifier means.
 10. The apparatus of claim 2 wherein the comparator means includes: an exclusive ''''OR'''' gate means receiving the encoded responder signal and the code identifier encoder means output signal providing an output signal in the ''''high'''' position in response to a difference between any one of the compared bits of the code element code and the identifier code, the ''''OR'''' gate means output signal providing a foreign code signal in the ''''high'''' position thereof indicating a difference between the compared code element code and the identifier code.
 11. The identifier apparatus of claim 1 controlling access to a secured area through an entrance or the like defined further to include: lock assembly means, having a locked and a release position and a portion engageable with a portion of the entrance or the like to substantially prevent access to the secured area via the entrance or the like in a locked position of the lock assembly means, the lock assembly means receiving the code valid signal and being positioned in the release position releasing the engagement between the lock assembly means and the entrance or the like for providing access to the secured area via the entrance or the like.
 12. The identifier apparatus of claim 11 wherein the identifier means is defined further to include a portion generating a foreign code signal in response to a responder signal encoded with a code other than the predetermined code generating the code valid signal; and wherein the apparatus is defined further to include: alarm means receiving the foreign code signal and producing an output indication in response thereto.
 13. The apparatus of claim 1 wherein the portion of the code element means receiving the interrogate signal and emitting the responder signal in response thereto is defined further to include: a binary encoder module, comprising: a program terminal connectable to a program power supply; a signal receiving terminal; a signal emitting terminal; encoder means connected to the signal receiving terminal, the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetermined code corresponding to the code element code and producing a signal encoded with the predetermined code element code connected to the signal emitting terminal in response to a received input signal receivable at the signal receiving terminal in an enabled position of the encoder means; means interposed between the encoder means and the program terminal encoding the predetermined code element code in the encoder means in response to a predetermined program power supply receivable at the program terminal, having a fuseable portion destroyable in response to a predetermined destruct signal receivable at the program terminal, the encoder means being permanently encoded with the code element code in a fused position of the fuseable portion; and means connected to the encoder means sequentially enabling the encoder means producing the signal encoded with the code element code at the signal emitting terminal.
 14. The apparatus of claim 13 wherein the portion of the identifier means identifying the received responder signal encoded with the code element code is defined further to include: a binary encoder module, comprising: a program terminal connectable to a program power supply; a signal receiving terminal; a signal emitting terminal; encoder means connected to the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetermined code corresponding to the identifier code and producing a signal encoded with the predetermined identifier code connected to the signal emitting terminal in response to an input signal receivable at the signal receiving terminal in an enable position of the encoder means; means interposed between the encoder means and the program terminal encoding the predetermined identifier code in the encoder means in response to a predetermined program power supply receivable at the program terminal, having a fuseable portion destroyable in response to a predetermined destruct signal receivable at the program terminal, the encoder means being permanently encoded with the identifier code in a fused position of the fuseable portion; and means connected to the encoder means sequentially enabling the encoder means producing the signal encoded with the identifier code at the signal emitting terminal.
 15. The apparatus of claim 14 wherein the binary encoder modules of the code element means and the identifier means are each defined further to include a plurality of encoder means; and wherein the means enabling the encoder means of the code element means and the identifier means are each further dEfined as connected to each encoder means sequentially enabling each encoder means producing the signal at the signal emitting terminal, the code encoded in each encoder means forming a portion of the code encoded in the signal at the signal emitting terminal.
 16. Apparatus for receiving an interrogate signal and emitting an encoded signal in response thereto when connected to a power supply, comprising: a code element; power contact means formed on a portion of the code element connectable to the power supply in one position of the code element; signal receiving contact means formed on a portion of the code element receiving the interrogate signal in one position of the code element; signal emitting contact means formed on a portion of the code element, the emitted encoded signal being connected to the signal emitting contact means in one position of the code element; code element encoder secured to a portion of the code element, having a portion connected to the power contact means, a portion connected to the signal receiving contact means and a portion connected to the signal emitting contact means, the code element encoder emitting a time oriented encoded responder signal connected to the signal emitting contact means in response to the received interrogate signal at the signal receiving contact means and the power source at the power contact means, the code encoded in the responder signal uniquely identifying the code element.
 17. A method for identifying code elements via an identifier wherein each code element is encoded with a predetermined code element code and each identifier is encoded with an identifier code, comprising: generating a clock signal having a predetermined frequency; receiving the clock signal at the code element and generating a time oriented responder signal encoded with the code element code in response thereto; receiving the clock signal at the identifier and generating a time oriented output signal encoded with the identifier code in response thereto; receiving and comparing the codes encoded in the responder signal and the identifier output signal; and producing code valid signal in response to identically compared codes encoded in the responder signal and the identifier signal.
 18. The method of claim 17 defined further to include the step of: positioning the code element in a code identifying position with respect to the identifier connecting a power supply to the code element and the identifier providing operating power therefor.
 19. The method of claim 18 wherein the step of positioning the code element and the identifier in a code identifying position is further defined as connecting the clock signal to the code element and connecting the responder signal to the identifier.
 20. The method of claim 17 further defined to include the step of: counting the number of identically compared bits of the code element code and the identifier code; and wherein the step of producing the code valid signal is further defined as producing the code valid signal in response to a predetermined number of counted identically compared bits of the code element code and the identifier code.
 21. A binary encoder module apparatus, comprising: a program terminal connectable to a program power supply; a signal receiving terminal; a signal emitting terminal; encoder means connected to the signal emitting terminal and to the program terminal, the encoder means having encoded therein a predetermined code for producing a signal encoded with the predetermined code connected to the signal emitting terminal in response to a signal received at the signal receiving terminal in an enable position of the encoder means; means interposed between the encoder means and the program terminal encoding the predetermined code in the encoder means in response to a predetermined program supply receivable at the program terminal, having a fuseable portion destroyable in response to a predetermined destruct signal receivable at the program terminal, the encoder means being permanently encoded with the predetermined code in a fused position of the fuseable portion; and means connected to the encoder means sequentially enabling the encoder means producing the encoded signal at the signal emitting terminal.
 22. The apparatus of claim 21 defined further to include a plurality of encoder means; and wherein the means enabling the encoder means is defined further as connected to each encoder means sequentially enabling each encoder means producing the signal at the signal emitting terminal, the code encoded in each encoder means forming a portion of the code encoded in the signal at the signal emitting terminal. 